Spraying mechanism



Jan. 22, 1963 J. s. KANAREK 3,074,650

SPRAYING MECHANISM Filed Feb. 26, 1959 2 Sheets-Sheet 1 United StatesPatent 3,074,650 SPRAYING MECHANISM Joseph S. Kanarek, Lombard, Ill.,assignor, by mesue assignments, to Ziif-Davis Publishing Company, NewYork, N .Y., a corporation of Delaware Filed Feb. 26, 1959, Ser. No.795,650 1 Claim. (Cl. 239-215) This invention relates to a sprayingmechanism and more particularly to a rotary mechanism adapted toattenuate liquids, such as paint and the like, and to discharge theattenuated liquid therefrom.

Spraying mechanisms embodying the present invention are of generalutility and may have any desired form and shape. An illustrativeembodiment of the present invention is in the form of a spray gun havinga pistollike grip or handle. The spray gun form of the invention isdescribed below in conjunction with the accompanying drawings as anillustrative embodiment of the invention. Also, the spray gun will bedescribed with reference to its use for spraying paint, although it maybe used with any suitable liquid.

The spray gun has a lower chamber or can for holding the paint. Aconveyor in the form of a feed screw or screw conveyor feeds the paintupwardly from the lower chamber to an upper chamber and an attenuator,which in this embodiment of the invention is a smooth surfaced invertedcone, is rotatably mounted in an upper chamber and receives the paintfed upwardly by the screw conveyor. A motor mounted in the mechanismrotates the screw conveyor for feeding paint and rotates the invertedcone to attenuate the paint. An adjustable shield controls the outletthrough which the attenuated paint is discharged. I

The inverted cone attenuator has a substantially flat outer peripheraledge portion" across which attenuated and filmed paint is discharged asa finely filmed spray substantially in the fiat plane of theflouter edgeportion of r the attenuator.

distanceabove the open top of the attenuator to cover the inverted coneattenuator to prevent excess discharged paint expelled from the sprayingmechanism as a whole, from rebounding or otherwise re-entering theattenuator from the;top. This prevents such excess paint from disturbingthe filming-out and attenuating action of the attenuator. By this meansa smooth and uniform spray is obtained without interference from excessdischarge from the attenuator and Without spattering or otherirregularitie's in the spray pattern. 7

The excess paint discharged from the attenuator is redirected and fedback to the lower chamber or paint can through communication openingsfrom the upper chamber, for reuse.

In addition to the valve assembly on the feed tube, the magnitude of thedischarge from the spray gun, and the width of the spray pattern arecontrolled by a shield arrangement on the spray gun. An inner shieldfixed to the top of the upper chamber has a skirt depending below thespace between the open top of the inverted cone and the flat disk. Aportion of the skirt, however, is cut away to provide part of adischarge outlet. An outer shield or gate is rotatably mounted betweenthe inner shield and the top of the upper chamber, and has a dependingskirt substantially of the same size and shape as the skirt of ice theinner shield. A lever fixed to the outer shield projects outwardlythrough a slot in the housing and is accessible for manually rotatingthe outer shield to vary the length of the discharge outlet formed bythe portions of the openings in the two shields in registration witheach other.

The maximum length of the discharge outlet is limited to the size of theopenings in the skirts of the shields, which, in this embodiment isabout one-fourth the circumference of the skirts, respectively. Thus, inthis embodiment of the invention, approximately seventy-five percent ofthe paint passing across the outer edge of the inverted cone strikes theinner surface of the inner shield, and a small additional portion of thepaint may strike the inner surface of the portion of the outer skirtwhich may overlap the opening in the inner skirt such as when theopenings in the two skirts are not in complete registration.

The skirts of the shields in addition to controlling the magnitude ofthe discharge from the spray gun, also are effective to redirect theexcess paint issuing from the attenuator, toward the bottom of the upperchamber for return through the communication openings to the can. Forthis purpose at least the upper portions of the skirts are formed assubstantially 45 cones and are radially aligned with the outer edgeportion of the attenuator so that excess paint issuing from theattenuator will strike the conical surfaces and be redirected asdescribed.

Some of the excess paint may find its way onto the top and edge of thecover plate or disk. To prevent this portion of the excess frominterferring with the spray pattern, the inner shield is provided with adoctoring blade having an edge closely adjacent the top surface and tothe edge of the cover plate. The plate rotates with the inverted cone,and the doctoring blade scrapes the paint from the top of the plate anddirects it to another doctoring blade which extends below the upper edgeof the inverted cone and removes excess paint from the edges of theattenuator and the disk cover plate. The paint removed in this mannerthen flows back into the lower chamber along with the rest of the excesspaint.

The structure by means of which the above-mentioned and other advantagesof the invention are attained will be described in the followingspecification, taken in conjunction with the accompanying drawingsforming a part of this specification, showing a preferred illustrativeembodiment of the invention, in which like reference numerals refer tolikeparts and in which:

FIGURE 1 is a front elevational view of a spray gun embodying theinvention;

FIGURE 2 is a side elevational view of the spray gun;

FIGURE 3 is a fragmentary vertical view, partly in elevation and partlyin section, showing the interior construction of the spray gun;

FIGURE 4 is a fragmentary vertical sectional view, showing the screwconveyor for feeding the paint into the inverted cone; and

FIGURE 5 is a detail perspective view of the inverted cone.

Referring to the drawings, the reference numeral 2 indicates a motorhousing in which is mounted a motor (not shown) having a drive shaft 3(FIGURE 4) depending therefrom. A hollow handle 4, fixed to housing 2 inany suitable manner forms a conduit for electrical wiring 5 forconnecting the motor to an electric current source. A switch (not shown)is mounted on the handle for controlling operation of the motor. Abarrel 6 having a cylindrical wall 7 is secured to the underside ofhousing 2 by a plurality of screws 8 (FIGURE 3). Barrel 6 has a lowertransverse wall 9 provided with a plurality of liquid return apertures10; and a skirt 11 depends from. thecylindrical wall 7 below thetransverse .wall 9.

A container or can engaging external thread 12 extends around theexternal circumferential face of the skirt 11.

Barrel 6 has an open top and fits against the bottom wall 2' of housing2 to form an upper chamber '13.

The upper end of a central tubular hub 14 fixed to transverse 'wall 9extends into chamber 13, and its lower end extends below the lower edgeof the cylindrical skirt 11 on 'the barrel 6. An integral arm 15extending upwardly at a slight angle from hub 14 to cylindrical wall 7is provided with an axial recess in threaded to receive a valve controlscrew 17 having a conical end 18. An aperture 19 extends through thelower wall of arm 15 adjacent to the inner end of recess 16.

The inner surface of hub 14 is threaded to receive a tubular sleeve 20which extends below the lower edge of hub 14, and a lock nut 21 isthreaded on the lower end of the sleeve to hold the hub and sleeveagainst accidental separation. The upper end of sleeve 26 is recessed onits outer surface, as indicated at 22, and the upper end of hub 14 isrecessed on its inner surface, as indicated at 23, to form an annularspace 24 between the upper end of sleeve 2% and the upper end of hub 14.An attenuator in the form of an inverted cone 25 disposed within thechamber formed by the barrel 6 and the transverse wall 2 of the housing2, is provided with a depending cylindrical flange 26 fitting loosely inspace 24. A washer 26' or other form of seal is provided between theupper 22d of the sleeve 20' and the lower end of the attenuator Avertical boss 27 extending upwardly from the apex region of the cone 25is provided with an axial bore 28 counterbored from the lower end, asindicated at .29, to form a shoulder 36. The outer surface of boss 27 isprovided with a plurality of external reinforcing ribs 31 and the lowerend of boss 27 is provided with a plurality of apertures 32 whichterminate substantially flush with annular shoulder 30.

The lower end or" drive shaft 3 has an axial bore 33 threaded to receivea screw 34 rigidly secured to the upper end of a screw conveyor 35.Screw 34 has an annular flange 36 abutting the upper end of screwconveyor 35. Flange 36 fits within counterbored portion 29 of boss 27and engages shoulder to support inverted cone 25. If desired, theinverted cone may be supported on the upper endof sleeve 20 or on thebottom of space 24.

Screw may be of any suitable material, but is preferably made of nylonwhich is inert and noncontaminating to liquids to be conveyed thereby.The screw 35 extends to a point spaced a short distance above the bottomof a can 37 or other receptacle which comprises the lower chamber of thespray gun. Can 37 is provided with a wide month which is threaded, asindicated at 38, to engage thread 12 of the skirt 11 on the barrel 6 sothat it may be easily attached to and removed from the spray .gun, forcleaning or filling. The can has no opening except its mouth, andcompletely encloses the lower portion of the spray gun.

A tube 3% is drive fitted into the lower end of sleeve 20 and cooperatestherewith to provide an open ended housing for screw 35. The lower endof tube 39 extends a short distance below the bottom of screw 35. Asplit, metal clamp 40 extends around tube 39 above its lower end. Theclamp is held against the tube with sufiicient friction to preventrelative movement therebetween. Clamp 40 has an integral extension 41extending downwardly and outwardly relative to tube 39. Extension 41 isbent, as indicated at 42, to provide a resilient, flat, valve plate 43extending across the open bottom of tube 39. A rigid, valve operatingrod 44 has one end secured to the free end of the plate 43 and the otherend 45 of the rod 44 projects through aperture 19 into tube 15.

As the screw 17 is threaded into tube 15 the conical end 18 of the screwengages the end 45 of rod 44 and forces the rod downwardly, therebymoving the resilient valve plate 43 away from the bottom f tube 39, The

.4 angle of extension 41 enables the resilience of the metal of whichplate 43 is formed to move the plate toward the bottom of tube 39 asscrew 17 is threaded outwardly relative to tube 15. Thus, the plate 43acts as a flap valve for the open end of tube 39, and the distancebetween plate 43 and the bottom of tube 39 controls the amount of paintthat is permitted to flow from the can 37 into the tube 39.

Boss 27 extends slightly above the plane of the upper end of invertedcone 25, and a disk-shaped cover plate 45, apertured tofit around driveshaft 3, is seated on the top of the boss. Plate 46 is held in positionby a sleeve 47 and a plurality of washers 48 which are mounted on thedrive shaft above the disk. The diameter of the plate 46 may besubstantially equal to or slightly greater than the diameter of theupper end of inverted cone 25 and is spaced therefrom to provide acontinuous opening 49 between the upper end of the inverted cone and thedisk throughout the circumference thereof, for flow of attenuated paintacross the llat outer edge portion 25' of the attenuator.

An inner shield 50' is rigidly secured to the bottom of motor housing'2by screws 51 and has an annular skirt 52 depending into upper chamber 13below opening 49. An outer shield 53 is rotatably mounted between innershield 56 and the bottom of motor housing 2. Shield 53 has a dependingskirt 54 of approximately the same size and shape as skirt 52. A fingeroperated lever 55 secured to outer shield 53 "projects through a slot 56in housing 2. Lever 55 may be manually manipulated to rotate outershield 53.

Each of skirts 52 and 54 has an opening which in this embodiment of theinvention is approximately one-fourth of the circumference of the skirtsto provide openings 57 and 58, respectively. When lever 55 is positionedto make opening 58 coincide with opening 57, the discharge outlet, whichcomprises the portions of openings 57 and 58 that are in registrationwith each other, has a length equal to about one-fourth of thecircumference of either skirt, which is the maximum length of thedischarge outlet. As lever 55 is moved from said position, the length ofthe discharge outlet is gradually reduced by movement of lever 55 in thesame direction, until the. discharge outlet is closed by the continuedrotation of outer shield 53 until opening 58 is completely out ofregistration with opening 57.

The skirts 52 and 54 of the shields 50 and 53, in addition tocontrolling the magnitude of the discharge from the spray gun, also areeffective to redirect the excess paint issuing from the attenuator,toward the bottom 2' of the upper chamber 13 for return through thecommunication openings 10 to the can 37. For this purpose at least theupper portions 52 and 54' of the skirts 52 and 54 are formed assubstantially 45 cones and are radially aligned with the outer edgeportion 25' of the attenu'ator 25 so that excess paint issuing from theattenuator will strike the conical surfaces 52 and 54 and be redirectedas described.

In the operation of the spray gun the screw 35 is rotatedcounter-clockwise, as viewed in FIGURE 4. This direction of rotation ofthe screw causes the groove 59 to move the paint in the groove upwardlyuntil it reaches the top of the screw. The paint then flows throughopenings 32 and is attenuated, filmed-out and spreads outwardly on thesurface of the rotating inverted cone. The paint moves upwardly on thesurface of the cone and is filmedout and increasingly attenuated untilit moves outwardly across or over the flat peripheral edge region 25' ofthe cone attenuator 25. The distribution of the paint around thecircumference of attenuator 25 is substantially uniform, and the paintis centrifugally sprayed across the edge portion 25 as a finely filmedspray.

The paint that impinges on the conical portions 52' and 54' of theshields 50 and 53 is directed thereby to flow through apertures 10 intothe lower chamber. Inner shield 50 is provided with doctoring blades 60and 61 that have edges arranged radially and axially of the plate 46 soclose to its upper surface and edge, respectively, that they scrapeexcess paint therefrom as the plate is rotated. Blade 60 terminatesadjacent to blade 61 that extends downwardly past the outer upper edgesof the plate 46 and the inverted cone 25 to remove excess painttherefrom and guide the paint downwardly into upper chamber 13, fromwhich it flows through apertures along with the excess paint from theinner surface of the skirts. Paint passing through apertures 10 fallsdirectly into the lower chamber from which it is again fed by screwconveyor 35.

The size of the pattern of paint sprayed may be regulated by adjustingthe length of the discharge outlet. This is done by rotating outershield 53 by means of lever 55. The amount of paint sprayed is afiectedby two factors, namely the distance between plate 43 and the bottom oftube 39, and by the speed of the motor. Paint may be sprayed from thegun continuously until the lower chamher is substantially empty, becausethe paint from the lower chamber will be fed upwardly into inverted cone25 as long as there is enough paint in the lower chamber to be engagedby screw 35.

Although I have described a preferred embodiment of the invention inconsiderable detail, it will be understood that the description thereofis intended to be illustrative, rather than restrictive, as many detailsmay be modified or changed without departing from the spirit or scope ofthe invention. Accordingly, I do not desire to be re stricted to theexact construction described.

I claim:

In a spraying mechanism, a lower chamber for containing a liquid to bedispensed, an upper chamber having a discharge outlet, a tube extendingfrom said upper chamher to said lower chamber, a rotatably mounted screwconveyor extending through said tube to carry liquid from said lowerchamber to said upper chamber, a resilient cover plate secured by aspring extension thereof and positioned against the open lower end ofsaid tube to regulate the flow of liquid into said tube, a rod securedto said cover, and means accessible from outside said lower chamber andengageable with said rod for moving said cover extension away from thelower end of said tube, the resiliency of said cover moving it towardthe lower end of said tube when pressure against said rod is released.

References Cited in the file of this patent UNITED STATES PATENTS2,023,710 St. Onge Dec. 10, 1935 2,064,125 Norris Dec. 15, 19362,086,921 Norris July 13, 1937 2,749,179 Almquist June 15, 19562,888,206 Waldrum May 26, 1959 UNITED STATES PATENT OFFICE CERTIFICATEOF CORRECTION Patent No. 3,074,650 January 22, 1963 Joseph S. Kanarek Itis hereby certified that error appears in the above numbered patentrequiring correction and that th e said Letters Patent should read ascorrected below.

Column 6, line- 15', strike out "extension"; line 16, after "cover"insert extension Signed and sealed this 20th day of August 1963.

(SEAL) lttest:

RNEST W. SWIDER xttesting Officer DAVID L. LADD Commissioner of Patents

